Deicer and pre-wetting agent

ABSTRACT

A liquid deicer composition suitable for use as a deicer or as a pre-coat for solid deicers is disclosed. The composition typically includes molasses solids, magnesium chloride, and a corrosion inhibitor. In one implementation the liquid deicer composition includes molasses solids; magnesium chloride, and a corrosion inhibitor.

FIELD OF THE INVENTION

[0001] The present invention relates to improved deicer compositions.More particularly, the invention is directed to molasses containingdeicers which have improved corrosion resistance, and are suitable foruse directly as deicers or as pre-wetting agents for solid deicers.

BACKGROUND

[0002] Solid deicers, such as rock salt (sodium chloride) and abrasives,such as sand, are commonly applied to roads and other surfaces duringwinter months. These solid deicers and abrasives are often pre-wettedbefore being stored or applied. Pre-wetting involves addition of aliquid to the solid deicer or abrasive in order to give it increasedresistance to freezing, improved storage characteristics, flowability,and deicing performance. Brines of sodium chloride, calcium chloride,and magnesium chloride are often used for this purpose. Unfortunately,these chloride based materials have a tendency to accelerate corrosionof automobiles, maintenance equipment, and infrastructure. Therefore, aneed exists for an improved deicer composition that is less corrosive,including a deicer composition that can be used alone or can be added tosolid deicers as a pre-wetting agent.

SUMMARY OF THE INVENTION

[0003] The present invention is directed to a liquid deicer compositionsuitable for use as a deicer or as a pre-coat for solid deicers. Thecomposition typically includes molasses solids, magnesium chloride, anda corrosion inhibitor. In one implementation the liquid deicercomposition includes from 1.0 to 70 percent molasses solids; from 0.1 to40 percent magnesium chloride; and from 0 to 30 percent of a corrosioninhibitor.

[0004] In specific embodiments the composition has less than 45 percentby weight molasses solids. Suitable molasses includes cane molasses,citrus molasses, wood molasses, grain molasses, and combinationsthereof. The magnesium chloride may be derived from liquid bittern,including liquid bittern containing 30 percent magnesium chloride. Insome implementations the bittern contains less than 20 percent magnesiumchloride by weight. Suitable corrosion inhibitors include phosphatesalts, such as orthophosphates, polyphosphates, pyrophosphates, andorganic phosphonates. Also, triethanolamine can be used as a corrosioninhibitor in accordance with the invention.

[0005] In addition to these ingredients, the composition can alsoinclude a solid deicer, such as sodium chloride, calcium chloride, urea,acetate salts, and combinations thereof. Suitable solid deicers includesodium chloride and magnesium chloride mixtures. The liquid compositioncan be applied by spray to the solid deicer as a pre-treatment toimprove the performance and application of the solid deicer. In mostimplementations the liquid composition is applied to the solid deicer ata mixing facility. Alternatively, the liquid composition can be appliedto the solid deicer at distributed locations, such as directly in adeicer dispensing truck. A useful composition containing a solid deicerincludes 0.5 to 13 percent by weight magnesium chloride; 0.6 to 1.5percent monosodium phosphate; 1.0 to 3.0 percent by weight molassessolids; and 82 to 96 percent by weight sodium chloride, all on a drysolids basis.

[0006] The above summary of the present invention is not intended todescribe each discussed embodiment of the present invention. This is thepurpose of the detailed description which follows.

DETAILED DESCRIPTION

[0007] The present invention is directed to a liquid deicer compositionsuitable for use as a deicer or as a pre-coat for solid deicers. Thecomposition typically includes molasses solids, magnesium chloride, anda corrosion inhibitor. In one implementation the liquid deicercomposition includes from 1.0 to 70 percent molasses solids; from 0.1 to40 percent magnesium chloride; and from 0 to 30 percent of a corrosioninhibitor.

[0008] As used herein, the term “molasses solids” refers to thecomponents of molasses that are not water, such as various carbohydrates(e.g. sugars) and proteins. Typical commercial grade molassescompositions used with the present invention are approximately 40 to 95percent molasses solids, more typically approximately 70 to 85 percentsolids. Specific suitable molasses compositions have about 80 percentsolids. Suitable molasses includes cane molasses, citrus molasses, woodmolasses, grain molasses, and combinations thereof.

[0009] The magnesium chloride may be derived, for example, from liquidbittern. As used herein, liquid bittern is a product derived from seasalt production, and is the liquid remaining after removal of sodiumchloride from seawater. Liquid bittern normally contains water alongwith a high concentration of magnesium chloride and lower concentrationsof other salts. In most implementations the liquid bittern contains from20 to 35 percent magnesium chloride. However, in other implementationsliquid bittern contains less than 20 percent magnesium chloride.

[0010] Suitable corrosion inhibitors include phosphate salts, such asorthophosphates, polyphosphates, pyrophosphates, and organicphosphonates. Also, triethanolamine can be use as a corrosion inhibitorin accordance with the invention. Diammonium phosphate and monosodiumphosphate are two specific phosphate salts that can be used individuallyor together to provide corrosion inhibition. Calcium phosphates are alsosuitable for use with the invention.

[0011] In addition to these ingredients, the composition can alsoinclude a solid deicer, such as sodium chloride, magnesium chloride,calcium chloride, urea, acetate salts, and combinations thereof. In suchimplementations the solid deicer is normally present in a significantlygreater quantity than the molasses solids or the corrosion inhibitor.Typically the amount of solid deicer is greater than twice the amount ofmolasses solids, and even more typically greater than ten times theamount of the molasses solids. The liquid composition may be applied byspray to the solid deicer as a pre-treatment to improve the performanceand application of the solid deicer. A suitable composition containing adeicer includes one or more phosphate salts, molasses solids, magnesiumchloride, and sodium chloride. Specific embodiments have at least 0.5percent by weight phosphate salt, at least 0.5 percent by weightmolasses solids, at least 2.0 percent by weight magnesium chloride, andat least 70 percent by weight sodium chloride. Example concentrationsfor the various components are 0.5 to 2.0 percent by weight of aphosphate salt, 0.5 to 2.0 percent by weight molasses solids, 2 to 6percent by weight magnesium chloride, and 80 to 97 percent by weightsodium chloride. These percentages are all given as relative percentagesto the other ingredients that are described. Additional ingredients(such as sand or water) can also be added to the composition, but do notchange the relative percentages of these ingredients.

[0012] Suitable specific compositions that can be used as a deicer caninclude greater than 0.5 percent by weight magnesium chloride, greaterthan 1.0 percent by weight molasses solids, and greater than 80 percentby weight sodium chloride. For example, a composition can contain from0.5 to 13 percent by weight magnesium chloride, from 1.0 to 3.0 percentby weight molasses solids, and from 85 to 96 percent by weight sodiumchloride. Specific compositions contain from 0.5 to 1.5 percent byweight monosodium phosphate, while other compositions contain up to 2.0percent by weight diammonium phosphate.

[0013] Other example compositions are 0.5 to 1.5 percent by weightmonosodium phosphate; 1.5 to 2.5 percent by weight liquid bittern; 1.5to 2.5 percent by weight cane molasses solids; and 90 to 96.5 percent byweight sodium chloride. The liquid bittern in this composition istypically from about 30 to 35 percent magnesium chloride. Thus, thecomposition contains from about 0.5 to 1.0 percent magnesium chloride.Another suitable composition comprises 0.5 to 1.5 percent by weightmonosodium phosphate; 0.5 to 1.0 percent by weight diammonium phosphate;1.5 to 2.5 percent by weight cane molasses solids; and 90 to 96.5percent by weight sodium chloride. Yet another suitable compositioncomprises 0.5 to 2.0 percent by weight monosodium phosphate; 1.5 to 2.5percent by weight cane molasses solids; 1.5 to 2.5 percent chloride salt(such as magnesium chloride or calcium chloride); and 90 to 96.5 percentby weight sodium chloride.

[0014] When added as a pre-wetting agent, the compositions of theinvention typically depress the freezing point of solid deicers orabrasives to which they are applied, and inhibit corrosion. Thus, thecompositions aid in reducing freezing and hardening of solid deicersinto large pieces that are difficult to apply. To test this aspect ofthe present formulations, rock salt with approximately 2 percentmoisture was stored at −4° F. for 24 hours and checked for flowability.Rock salt samples containing 4.3 percent by weight of a pre-wettingagent containing 50 percent cane molasses (which was approximately 80percent molasses solids) and 50 percent liquid magnesium chlorideremained flowable, while the rock salt without the pre-wetting agent wasfrozen solid.

[0015] In order to demonstrate the improved properties of compositionsformulated in accordance with the present invention, liquid magnesiumchloride derived from solar salt production (liquid bittern) was testedfor corrosiveness when blended with varying levels of cane molasses. Totest this corrosiveness, 1/2 inch flat steel washers meeting ASTMSpecification F436, Type 1 were exposed to 3 percent by volume dilutionsof different liquid formulations. Triplicate sets of washers weresubjected to repeated cycles of 10 minutes immersion in the testsolution followed by 50 minutes of air drying for a period 72 hours. Theresults of this test are shown below in Table 1: TABLE 1 FormulationCorrosion Rate (MPY*) 100% liquid bittern 30 5% cane molasses, 95%liquid bittern 17 50% cane molasses, 50% liquid bittern  8

[0016] Table 1 demonstrates a significant decrease in the corrosivenessof the liquid deicer when molasses is added to the liquid. Even arelatively small dose of molasses can have a dramatic improvement incorrosion resistance, as demonstrated by the formulation containing just5 percent molasses. An even greater improvement is demonstrated whenequal portions of cane molasses and liquid bittern are combined, asdemonstrated in the last formulation.

[0017] The synergistic effect of the molasses and liquid bittern withother corrosion inhibitors as a treatment for solid sodium chloridedeicers was tested by using the liquid deicer composition as apre-wetting agent on solid sodium chloride. The pre-wetting agentincluded 50 percent cane molasses and 50 percent liquid bittern (ofwhich 30 percent was magnesium chloride). To test corrosiveness, ½ inchflat steel washers meeting ASTM Specification F436, Type 1 were exposedto 3 percent by weight dilutions of different solid formulations.Triplicate sets of washers were subjected to repeated cycles of 10minutes immersion in the test solution followed by 50 minutes of airdrying for a period 72 hours. The results of this test is shown below inTable 2: TABLE 2 Corrosion Deicer Composition Rate (MPY) 100% sodiumchloride 51 99.1% sodium chloride, 0.9% MSP 30 95.7% sodium chloride,4.3% pre-wetting agent 42 94.8% sodium chloride, 4.3% pre-wetting agent,0.9% MSP 15

[0018] As demonstrated in Table 2, the composition with the greatestreduction in corrosion was the composition containing the pre-wettingagent and the mono sodium phosphate (MSP). Untreated sodium chloridedemonstrated a corrosion rate of 51 mils per year, and treatment withonly MSP achieved a reduction of corrosion to 30 MPY. Use of only thepre-wetting agent decreased corrosion to 42 MPY. However, treatment withthe combination of MSP and the pre-wetting agent brought the corrosionrate down by 36 MPY to 15 MPY. Thus, in the example tested, a verysignificant complimentary effect was observed by combining the corrosionreducer with the molasses-containing pre-wetting agent. Althoughphosphates have been used as corrosion inhibitors for deicers, it isdesirable to reduce the level of phosphate as much as possible to reducecost as well as to reduce the amount of phosphate put into theenvironment.

[0019] While the present invention has been described with reference toseveral particular implementations, those skilled in the art willrecognize that many changes may be made hereto without departing fromthe spirit and scope of the present invention.

We claim:
 1. A deicer composition, the composition comprising on awater-free basis: from 1.0 to 70 percent by weight molasses solids; from0.1 to 40 percent by weight magnesium chloride; and from 0 to 30 percentby weight of a corrosion inhibitor.
 2. The deicer composition accordingto claim 1 , wherein the composition comprises less than 45 percent byweight molasses solids.
 3. The composition according to claim 1 ,wherein the molasses is derived from cane molasses, citrus molasses,grain molasses, and combinations thereof.
 4. The composition accordingto claim 1 , wherein the magnesium chloride is derived from liquidbittern.
 5. The composition according to claim 1 , wherein thecomposition comprises less than 25 percent magnesium chloride.
 6. Thecomposition according to claim 1 , wherein the corrosion inhibitor is aphosphate salt.
 7. The composition according to claim 6 , wherein thephosphate salt is selected from the group consisting of orthophosphates,polyphosphates, pyrophosphates, organic phosphonates, and combinationsthereof.
 8. The composition according to claim 7 , wherein the phosphatesalt is selected from the group consisting of diammonium phosphate,monosodium phosphate, and calcium phosphate.
 9. The deicer compositionaccording to claim 1 , wherein the corrosion inhibitor istriethanolamine.
 10. The deicer composition according to claim 1 ,wherein the composition further comprises a solid deicer.
 11. The deicercomposition according to claim 10 , wherein the solid deicer is selectedfrom the group consisting of potassium chloride, magnesium chloride,sodium chloride, calcium chloride, urea, acetate salts, and combinationsthereof.
 12. A deicer composition, the composition comprising on awater-free basis: at least 0.5 percent by weight magnesium chloride; atleast 0.5 percent by weight molasses solids; and at least 80 percent byweight sodium chloride.
 13. The deicer composition of claim 12 , whereinthe composition comprises on a water-free basis: 0.5 to 13 percent byweight magnesium chloride; 0.5 to 3.0 percent by weight molasses solids;and 85 to 96 percent by weight sodium chloride.
 14. The deicercomposition of claim 12 , wherein the deicer contains from 0.5 to 1.5percent by weight monosodium phosphate.
 15. The deicer composition ofclaim 12 , wherein the deicer contains up to 2.0 percent by weightdiammonium phosphate.
 16. A deicer composition, the compositioncomprising: a) one or more phosphate salts; b) molasses solids; c)chloride salt; and d) sodium chloride.
 17. The deicer composition ofclaim 16 , wherein the composition based upon water-free weightcomprises: at least 0.5 percent by weight phosphate salt; at least 0.5percent by weight molasses solids; at least 2.0 percent by weightmagnesium chloride; and at least 70 percent by weight sodium chloride.18. The deicer composition of claim 17 , wherein the phosphate saltcomprises monosodium phosphate.
 19. The deicer composition of claim 17 ,wherein the phosphate salt comprises diammonium phosphate.
 20. Thedeicer composition of claim 16 , wherein the composition based uponwater-free weight comprises: 0.5 to 2.0 percent by weight of a phosphatesalt; 0.5 to 2.0 percent by weight molasses solids; 2.0 to 6.0 percentby weight magnesium chloride and 80 to 97 percent by weight sodiumchloride.
 21. The deicer composition of claim 20 , wherein the phosphatesalt comprises monosodium phosphate.
 22. The deicer composition of claim20 , wherein the phosphate salt comprises diammonium phosphate.